Structural and transport properties of Li1 + xV1 − xO2 anode materials for Li-ion batteries

Recently, layered Li1 + xV1 − xO2 with x ≥ 0 has attracted significant attention as an anode material for Li-ion batteries. Its high volumetric and gravimetric capacities (1360 mAh·cm− 3 and 300 mAh·g− 1 respectively) make it particularly interesting. During lithium intercalation Li1 + xV1 − xO2 with x > 0 exhibits wide potential plateau below 0.1 V vs. Li/Li+, while for stoichiometric LiVO2 lithium uptake hardly occurs. In this work evaluation of crystal structure, transport and electrochemical properties is given for Li1 + xV1 − xO2 materials with x = 0, 0.03 and 0.07. Li1 + xV1 − xO2 showed activated character of conductivity with activation energy about 0.2-0.3 eV. Thermoelectric power values exceeding 80 μV·K− 1 point to electron holes as the main charge carriers. Thermogravimetric measurements carried out in air indicated only minor variations of mass of the materials up to 215 °C, suggesting high stability along with low level of oxygen nonstoichiometry.